The little girl who dubbed herself Mrs. Justin Bieber after a Valentine’s Day meeting with her pop idol has lost her battle with cancer. Six-year-old Avalanna Routh died from a rare form of brain cancer on Wednesday morning. Her parents took to Twitter.com to announce the sad news, writing, “Our darling Avalanna went to Heaven this morning. “Oh Avalanna, the brightest star – you took our hearts with you, our greatest Love.” Routh hit the headlines in February when Bieber surprised her with a date in New York and staged a mock wedding. He later tweeted, “That was one of the best things I have ever done. She was awesome!” Bieber and Routh reunited in June for a U.S. TV interview. Upon hearing the news of his tragic friend’s death on Wednesday, Bieber wrote, “just got the worst news ever. one of the greatest spirits i have ever known is gone. please pray for her family and for her… RIP Avalanna. i love you. “Please show respect to her and her family… i miss her.”